I think that Dennis Ritchie will be mentioned in texts of students learning computer science, programming languages, and operating systems for many many years. He will be remembered as Pythagoras, Cantor, and Turing are.

Jobs was a celebrity and much of the coverage is due to it. That is not to say Jobs was only a celeb and nothing more. Time will tell, but I have a feeling that memories and texts mentioning Ritchie will linger over time while memories and texts of Jobs will dwindle.